62 SAMUEL H. SCUDDER ON THE SPREAD 



there until 1878, when Mr. W. V. Andrews found it in March at Asheville. The south- 

 ern pai't of our line for this year is, therefoi'e, purely conjectural, as are also the lines for 

 the southern colonies, from which we have no data. 



There enters now a good deal of confusion in the dates of its appearance as ohtained 

 by correspondence in differeut parts of tlie west. The insect had become abundant on 

 all the main railway lines runniug east and west aud was liable to be forcibly carried in 

 auy direction. Wherever a pair, male and female, happened after all vicissitudes to come 

 together, there would be the poiut for the introduction of a new colony; for mignonette 

 or cabbage or turnip would be found somewhere about; and the only wonder is that 

 the movement of the throng was as regular as it was. 



Dui-ing 187G it covered the whole of western Ontai'io (Saunders loc. cit. ) and extended 

 into castei-n Michigan (A. J. Cook) ; Mr. E. A. Strong even states that he took it at 

 Grand I\ai)ids in 1875, but this I think must be a fault of recollection. Below 

 the Lakes however, it moved on more rapidly. It is possible, if not probal)le, 

 that one of the roadside colonies to which I aUuded above was estabhshed in central 

 Indiana before this, for Mr. S. G. Evans says that Pieris rapae was common in Evans- 

 ville when he commenced collecting thei-e in 1874; and Dr. G. M. Levette writes me 

 from Indianapolis, "From recollections of myself and others I would place it [the in- 

 troduction of P. rcqjae at that point] in 1872 or 1873." We have the very definite state- 

 ment from Dr. F. W. Croding that he captured a female in his father's gai'den in Kane 

 Co., 111., 41 miles west of Chicago on Sept. 17, 1875. A few days afterward he saw sev- 

 eral, as he now distinctly remembers, in cabbage fields west of Chicago, flying in com- 

 pany with P. pfofodice. Mr. J. W. Iluett also writes that he first saw the butterfly at 

 Farm Ridge, LaSalle Co., in the spring of 1874 or 1875, in scanty niimbers. It would 

 therefore appear highly probable that, a year or two in advance of the normal rate of 

 progress. Pier-is rapae swejit into Chicago on a railway train. We have no further i-ecord 

 for this year of the advance of the great horde, but simply from analogy and subsequent 

 facts, the curve of its probable progress has been placed on the map. 



In 187G, however, we have indications of the spread of both of the southern colonics, 

 for in October of this year. Dr. A. Oemler detected the butterfly at Wilmington Island 

 off Savannah, — evidently an extension of the Charleston colony of 1873; while the fact 

 that the butterfly was as common in 187G as now at Lumpkin in the southwestern part 

 of the state, as I am infoi-med by Mr. A. W. Latimer, indicates the spread of the Apa- 

 lachicola colony. 



In 1877, to begin now with the south, these two southern colonies probably merged, 

 for the buttei'fly was common at Macon, as reported by Prof. J. E. Willet at the August 

 meeting of the Georgia Horticultural Society, a point which i)r(jbably might 

 have been reached by either colony this year, though not by the northern horde 

 for a year or two later, to judge by all accounts. For, to forestall the succeeding yeai'S 

 a little, the pest was not noticed in northern Alabama until 1879, nor at Atlanta, Georgia, 

 until 1880, nor at Chester, S. C, until 1881 (L. M. Loomis). 



From these points to Illinois is a long leap, but for this j'car it has no record. Ex- 

 cepting for the notice of its common occurrence at the head of Lake IJosseau in the 

 Muskoka District, east of Georgian Bay, Canada (Saunders, Can. Ent. is, 185), the only 



